In household electrical appliances, audio visual appliances, personal computer equipment, office automation equipment, industrial machines or other electronic devices, a capacitive touch switch module is used as one of input devices to each appliance. The capacitive touch switch module is connected to a microcomputer. The microcomputer converts a change amount of capacitance of each of sensor electrodes served as a switch installed in a touch switch panel, into a numerical value. When the value exceeds a predetermined threshold, the microcomputer determines that a finger touches the touch switch panel.
In order to show clearly that the switch of the touch switch module is activated, a light emitting diode (hereinafter, referred to as an LED) backlight is generally installed at a back side of the sensor electrode. Ina case in which the number of the LED backlights is increased, the touch switch might be affected by the driving of the LEDs thereof.
Conventionally, an LED lighting device provided with a converter capable of executing both of power factor improving control and constant current control necessary for driving a plurality of the LEDs, is known (Japanese Unexamined Patent Application Publication No. 2015-084616). Further, an LED luminaire capable of suppressing generation of EMI by reducing an electromagnetic noise generated in an LED lighting device, is known (Japanese Unexamined Patent Application Publication No. 2013-062032).